Contributions of AMPA and GABA(A) receptors to the induction of NMDAR-dependent LTP in CA1.
The contributions of (+/-)-alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA) and gamma-aminobutyric acid (GABA[A]) receptors in the induction of long-term potentiation (LTP) have been studied in the CA1 region of the rat hippocampus. The results suggest that: (1) in physiological conditions, AMPARs are necessary for the induction of N-methyl-D-aspartate receptor (NMDAR)-dependent LTP since LTP cannot be elicited in the presence of the AMPAR antagonist, 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX). Although a NMDAR-dependent LTP occurs in the presence of a GABA(A) antagonist and high concentrations of divalents cations, blockade of AMPARs leads to a voltage-dependent calcium channels (VDCC)-dependent LTP since its induction is blocked by nifedipine and not by APV. (2) The bicarbonate-induced GABA(A) receptor-mediated depolarizing response is not necessary in the induction of NMDAR-dependent or VDCC-dependent LTP since induction of these two types of LTP were not blocked by acetazolamide or in a nominally bicarbonate-free solution.
Debray
C
C
Institut National de la Santé et de la Recherche Médicale U-29, Paris, France.
Diabira
D
D
Gaiarsa
J L
JL
Ben-Ari
Y
Y
Gozlan
H
H
D015763:2-Amino-5-phosphonovalerate / Q000494:pharmacology; D018750:6-Cyano-7-nitroquinoxaline-2,3-dione / Q000494:pharmacology; D000818:Animals; D001640:Bicuculline / Q000494:pharmacology; D019706:Excitatory Postsynaptic Potentials / Q000187:drug effects; D006624:Hippocampus / Q000187:drug effects / Q000502:physiology*; D066298:In Vitro Techniques; D017774:Long-Term Potentiation / Q000187:drug effects*; D008297:Male; D009543:Nifedipine / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D018091:Receptors, AMPA / Q000502:physiology*; D011963:Receptors, GABA-A / Q000502:physiology*
D018091:Receptors, AMPA; D011963:Receptors, GABA-A; D018750:6-Cyano-7-nitroquinoxaline-2,3-dione; D015763:2-Amino-5-phosphonovalerate; D009543:Nifedipine; D001640:Bicuculline